The present invention relates to a solution for making bubbles.
A bubble may be defined as a small volume of gas contained within a thin liquid spherical envelope. Bubble-making toys and devices are well known, and numerous toys and related products of this type are available commercially due to the popularity of these devices with children. A common operating principle of these toys or devices is that one or more openings is provided, such as the ring-end of a wand device upon which a soapy bubble-forming solution film is formed by immersion or other means. Surface tension causes the bubble solution to form the film across the opening, and upon application of a sufficient force or gas pressure upon one side of the film, a bubble is formed and expelled from the opening in the direction in which the force is exerted.
Bubble-forming devices can range from the most basic, such as the above-described wand having the ring at one end for dipping into a bubble solution, to more sophisticated devices such as mechanized bubble-producing toys that may include pumps or other features designed to facilitate production of bubbles by the user. Examples of mechanized or complex bubble-producing devices are described in U.S. Pat. Nos. 6,024,623, 5,908,057, 5,879,218, 5,746,636, 5,704,821, 5,695,379, 5,613,890, and 5,603,651, to name but a few. Other bubble-producing toys, for example a bubble-forming lawn mower-style device sold by Fisher-Price(copyright), are also available commercially.
Improvements in the art of bubblemaking toys to date have focused on modifications to the bubblemaking device itself rather than to the bubblemaking solution. For example, the device described in U.S. Pat. No. 6,024,623 includes a frustoconical surface having a precise upward angle of about 30 degrees to prevent bubbles exiting the aperture from contacting the handle and bursting prematurely. The problem of bubble bursting immediately upon contact with a solid object or surface including that of the device itself can therefore necessitate specific product design efforts to minimize the undesirable effect. This leads to increased product development cost, increased design complexity, and increased tooling and manufacturing costs.
A typical toy bubble solution contains water mixed with one or more soaps. The soap has the effect of decreasing the surface tension of the water so that when a ring or similarly apertured surface is immersed or otherwise contacted with the solution, a film is formed across the opening. A gas, generally air, is pushed or forced against one surface of the film, which displaces the film from the apertured surface and produces a free-floating bubble.
The present invention relates to an aqueous bubble solution. The solution has at least a surfactant that produces micelles in an aqueous solution, along with an ionic, hydrophobic or hydrogen bonding agent that interacts with the surfactant. When the bubble solution is formed into a bubble the bubble provides a first predetermined effect other than just being formed and popping.
The bubble solution of the present invention forms bubbles having good integrity and that are relatively long-lasting. Unlike prior art formulations, when bubbles produced according to this invention burst the resulting product is an integral or cohesive strand, drop, or sheet. The resulting product provides an interesting and unique appearance to the user. These drops, strands, or sheets may have anywhere from a white appearance to a transparent one, with the color depending on factors such as the presence of water remaining in the bubble at the time of rupture and/or the presence and concentration of other ingredients in the bubble solution. The improved bubbles also tend to opacify and phase change from a liquid (phase) bubble to a solid (phase) bubble without bursting. The use of the term xe2x80x9csolidxe2x80x9d in the preceding statement and as used below is meant to describe the phase change, or reverse phase change, that occurs with some liquids. For example, when a Pluronics F127 solution is heated, it gels rather than to a gas as with most liquids. The transition may alternatively be described as from a liquid bubble to a solid plastic. This solid bubble sometimes bursts and creates a xe2x80x9cparachutexe2x80x9d effect.
The bubble solution of the invention may be used with any simple or complex bubblemaking device, machine, or other bubblemaking apparatus to produce bubbles having the improved characteristics and appearance.
In one embodiment, a bubble solution according to the invention includes water and a soap or mixture of soaps, for example, each soap having a carbon chain of from about 12 to about 18 carbon atoms and including a water-soluble polar end such as xe2x80x94COONa or SO3Na and a non-polar, oil-soluble end. The bubble solution further includes a water-soluble polymer of 500 daltons or more or polymer surfactant having a molecular weight of 500 daltons or more and having both hydrophilic and hydrophobic portions.
The water-soluble polymer may comprise one or more of the following polymers: poly(N,N-dimethyl acrylamide (pDMA)), poly(2-hydroxyethyl methacrylate (pHEMA)), poly(glycerol methylacrylate), poly(2-hydroxyethyl methacrylamide), polyethleneglycol, poly(methacrylic acid), poly(acrylic acid), poly(N-vinyl pyrolidone) (PVP), poly(N-vinyl-N-methyl acetamide), poly(N-vinyl-N-ethyl acetamide), poly(N-vinyl-N-ethyl formamide) and poly(N-vinyl formamide). The polymers can also be copolymers or terpolymers or the like, that is, polymers composed from the monomeric unit of the polymers just described.
The surfactant can be selected from a cationic, anionic, zwitterionic, or nonionic surfactant or combinations thereof, and can be either polymeric or non-polymeric. The polymer surfactants have hydrophilic and hydrophobic portions; co-(ethylene oxide, proplene oxide) (Pluronics(copyright) polymer by BASF), co-(ethylene oxide, proplene oxide)-ethylenediamine (Tetronics(copyright) polymer by BASF). A polymer as described above may be present with or without the surfactant.
The water soluble polymer preferably comprises from about 1% to about 90% by weight but most preferred 10-50% by weight or surfactant component preferably comprises from about 1% to about 90% by weight but most preferred 10-30% in the bubble solution.
The bubble solution optionally includes suitable viscosity-inducing components, thickening agents, or emulsions that include hydrophobic molecules, including but not limited to glycerin, water-soluble natural gums, and cellulose-derived polymers and the like. For example, the presence of glycerin in the solution has been noted as contributing to extending the life of a bubble, such as is described in U.S. Pat. No. 5,613,890.
Useful natural gums include guar gum and gum traganth and the like. Useful cellulose-derived polymers include hydroxypropyl cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose, methyl cellulose, and hydroxyethyl cellulose, and the like. The viscosity-inducing or thickening agent is preferably selected from cellulose derivatives (polymers) and mixtures thereof.
Useful polymer surfactants suitable as the surfactant component in the bubble solution according to the invention include those described in U.S. Pat. No. 5,177,165, as follows.
The terms xe2x80x9c(meth)acrylatexe2x80x9d or xe2x80x9c(meth)acrylamidexe2x80x9d denote methyl substitution and therefore includes both methyl acrylate and methyl methacrylate, while N-alkyl (meth)acrylamide includes both N-alkyl acrylamide and N-alkyl methacrylamide.
Surfactant copolymers useful in the invention are prepared by copolymerizing at least one ethylenically unsaturated hydrophobic monomer and at least one ethylenically unsaturated hydrophilic monomer in the presence of a functional chain transfer agent. Preferred copolymers have the formula:
C[AxBy]
wherein A is at least one ethylenically unsaturated hydrophilic monomer, B is at least one ethylenically unsaturated hydrophobic monomer, C is a functional chain transfer agent, y is within the range of about 0.1 to about 0.9, and x+y=1.
Suitable ethylenically unsaturated hydrophilic monomers (xe2x80x9cAxe2x80x9d in the above formula) include ethylenically unsaturated polyoxyalkylenes, polyacrylamides, polyvinylpyrrolidones, polyvinyl alcohols, poly (hydroxyethyl methacrylate) or poly (HEMA), and N-alkyl-N-vinyl acetamides. Ethylenic unsaturation may be provided by (meth)acrylate, (meth)acrylamide, styrenyl, alkenyl, vinyl carbonate and vinyl carbamate groups. Preferred hydrophilic macromonomers include methoxypolyoxyethylene methacrylates of molecular weights from 200 to 10,000, more preferred are methoxypolyoxyethylene methacrylates of molecular weight range of 200 to 5,000 and most preferred are methoxypolyoxyethylene methacrylates of molecular weight range of 400 to 5,000. Additional preferred hydrophilic macromonomers include poly-N-vinylpyrrolidone methacrylates of molecular weights of 500 to 10,000. More preferred are poly-N-vinylpyrrolidone methacrylates of molecular weights of 500 to 5,000 and most preferred are poly-N-vinylpyrrolidone methacrylates of molecular weights of 1000 to 5,000. Other preferred hydrophilic macromonomers include poly-N,N-dimethyl acrylamide methacrylates of molecular weights of 500 to 10,000. More preferred are poly-N,N-dimethyl acrylamide methacrylates of molecular weights of 500 to 5,000 and most preferred are poly-N,N-dimethyl acrylamide methacrylates of molecular weights of 1000 to 5,000.
Suitable ethylenically unsaturated hydrophobic monomers (xe2x80x9cBxe2x80x9d in the above formula) include alkyl (meth)acrylates, N-alkyl (meth)acrylamides, alkyl vinylcarbonates, alkyl vinylcarbamates, fluoroalkyl (meth)acrylates, N-fluoroalkyl (meth)acrylamides, N-fluoroalkyl vinylcarbonates, N-fluoroalkyl vinylcarbamates, silicone-containing (meth)acrylates, (meth)acrylamides, vinyl carbonates, vinyl carbamates, styrenic monomers [selected from the group consisting of styrene, alpha-methyl styrene, para-methyl styrene, para-t-butyl monochloro styrene, and para-t-butyl dichloro styrene] and polyoxypropylene (meth)acrylates. Preferred hydrophobic monomers include methyl methacrylate, dodecyl methacrylate, octafluoropentyl methacrylate, perfluorooctyl methacrylate, methacryoyl oxypropyl tris(trimethylsiloxy)silane (TRIS).
The functional chain transfer agent (xe2x80x9cCxe2x80x9d in the above formula) controls the molecular weight of the copolymer. Suitable functional chain transfer agents include mercapto carboxylic acids, mercapto alcohols (also known as hydroxymercaptans), and aminomercaptans. Preferred chain transfer agents include thioglycolic acid, 2-mercaptoethanol and 2-aminoethane thiol. The molar ratio of chain transfer agent to total monomer content used in the copolymerization is preferably in the range of 0.01 to 3, more preferably in the range of 0.02 to 2, and still more preferably in the range of 0.05 to 1.
Suitable surface active macromonomers of the invention are described by the formula:
DC[AxBy]
wherein A, B, C, x and y are as described above and D is an ethylenically unsaturated end group. Selection of the ethylenically unsaturated end group (xe2x80x9cDxe2x80x9d in the above formula) is determined by the functional group of the functional chain transfer agent. For example, if the chain transfer agent contains a carboxylic acid group, glycidyl methacrylate can provide a methacrylate end group. If the chain transfer agent contains hydroxy or amino functionality, isocyanato ethyl methacrylate or (meth)acryloyl chloride can provide a methacrylate end group and vinyl chloro formate can provide a vinyl end group.
Suitable hydrophilic monomers include water soluble monoesters of (meth)acrylic acid with an alcohol having an esterifiable hydroxyl group and at least one additional hydroxyl group such as the mono- and poly-alkylene glycol monoesters of (meth)acrylic acid, e.g., ethylene glycol mono(meth)acrylate, diethylene glycol mono(meth)acrylate, propylene glycol mono(meth)acrylate, dipropylene glycol mono(meth)acrylate, and the like; the N-alkyl and N,N-dialkyl substituted (meth)acrylamides such as N-methyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, and the like; N-vinylpyrrolidone and the alkyl substituted N-vinyl pyrrolidones; glycidyl (meth)acrylates; the unsaturated amines; the alkoxy ethyl acrylates; mixtures thereof; and the like.
Suitable di- or higher polyfunctional species cross-linking agents include divinylbenzene, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, and the (meth)acrylate esters of polyols such as triethanolamine, glycerol, pentaerythritol, butylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, mannitol, and sorbitol, N,N-methylene-bis-(meth)acrylamide, sulfonated divinylbenzene, and divinylsulfone.
The soap component of the bubble solution may comprise a commercially available product such as Miracle Bubble(copyright), Ultra Dawn(copyright), or Ultra Palmolive(copyright) and may comprise one of the following commercially available formulations, and which are further described in U.S. Pat. No. 5,415,814.
The soap formulation may include a surfactant, with or without a surfactant and/or polymer as described above, and a source of calcium ions in the form of calcium xylene sulfonate, calcium chloride with sucrose optionally included for stability. The surfactant, present in an amount of from about 20% to about 95% by weight, may comprise an anionic surfactant with an associated cation selected from an alkali metal, ammonium, mono-, di-, and tri-ethanolammonium, such as sodium, potassium, ammonium and mixtures thereof. Suitable anionic surfactants include (a) alkyl benzene sulfonates in which the alkyl group contains from 9 to 15 carbon atoms, preferably 11 to 14 carbon atoms in straight chain or branched chain configuration; (b) alkyl sulfates obtained by sulfating an alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, and described by the formula ROSO3xe2x80x94M+ where R is a C8-22 alkyl group and M is a mono- and/or divalant cation; (c) paraffin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety, and commercially available as Hostapur SAS from Hoechst Celanese; (d) olefin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms; (e) alkyl ether sulfates derived from ethoxylating an alcohol having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, less than 30, preferably less than 12, moles of ethylene oxide, and described by the formula RO(C2H4O)xSO3xe2x80x94M+ where R is a C8-22 alkyl group, x is 1-30, and M is a mono- or divalent cation; (f) alkyl glyceryl ether sulfonates having 8 to 22 carbon atoms, preferably 12 to 16 carbon atoms, in the alkyl moiety; (g) fatty acid ester sulfonates of the formula R1xe2x80x94CH(SO3xe2x80x94M+)CO2R2 wherein R1 is straight or branched alkyl from about C8 to C18, preferably C12 to C16, and R2 is straight or branched alkyl from about C1 to C6, preferably primarily C1, and M+ represents a mono- or divalent cation; (h) secondary alcohol sulfates having 6 to 18, preferably 8 to 16 carbon atoms; (i) alkyl diphenyl oxide disulfonate surfactants of the general formula: 
Rxe2x95x90C10-C18, may be branched or linear, R1xe2x95x90H or R, Mxe2x95x90Na+, K+, NH4+, Ca++, or Mg++; and 
Rxe2x95x90C10-C18, may be branched or linear, R1xe2x95x90H or R, M1xe2x95x90Ca++ or Mg++. Rxe2x95x90C10-C18, may be branched or linear, R1xe2x95x90H or R, M1xe2x95x90Ca++ or Mg++. Suitable series from Dow Chemical (Dowfax 2A1, 3B2, 8290) and the POLY-TERGENT.RTM. series from Olin Corp., preferably in an amount from about 0.5% to about 40% by weight.
Other suitable polymers include C10-C16 secondary carboxyl materials of the formula R3CH(R4)COOM, wherein R3 is CH3(CH2)x and R4 is CH3(CH2)y, wherein y can be 0 or an integer from 1 to 6, x is an integer from 6 to 12 and the sum of (x+y) is 6-12, preferably 7-11, most preferably 8-9; carboxyl compounds wherein the carboxyl substituent is on a ring hydrocarbyl unit, i.e., secondary soaps of the formula R5xe2x80x94R6xe2x80x94COOM, wherein R5 is C7-C10, preferably C8-C9, alkyl or alkenyl and R6 is a ring structure, such as benzene, cyclopentane, cyclohexane, and the like, and where R5 may be in the ortho, meta or para position relative to the carboxyl on the ring; C10-C18 primary and secondary carboxyl compounds of the formula R7CH(R8)COOM, wherein the sum of the carbons in R7 and R8 is 8-16, R7 is of the form CH3(CHR9)x and R8 is of the form H(CHR9)y, where x and y are integers in the range 0-15 and R9 is H or a C1-4 linear or branched alkyl group, R9 is any combination of H and C1-4 linear or branched alkyl group members within a single xe2x80x94(CHR9)x,y group, while each molecule should contain at least one R9 that is not H; C10-C18 tertiary carboxyl compounds, e.g., neo-acids, of the formula R10CR11(R12)COOM, wherein the sum of the carbons in R10, R11 and R12 is 8-16, R10, R11, and R12 are of the form CH3xe2x80x94(CHR13)x, where x is an integer in the range 0-13, and R13 is H or a C1-4 linear or branched alkyl group, and R13 is any combination of H and C1-4 linear or branched alkyl group members within a single xe2x80x94(CHR13)x group: suitable commercially available such compounds include the neodecanoic acid manufactured by Exxon and the Versatic(copyright) acids manufactured by Shell; and mixtures thereof. In the above formulas, xe2x80x9cMxe2x80x9d is any suitable counterion, e.g., H, alkali metal, alkaline earth metal, ammonium, alkanolammonium, di- and tri-alkanolammonium, C1-C5 alkyl substituted ammonium and the like.
Suitable nonionic detergent surfactants include the polyethylene, polypropylene, and polybutylene oxide condensates of alkyl phenols, including Igepal(trademark) CO-630, marketed by the GAF Corporation; and Triton(trademark). X-45, X-114, X-100, and X-102, all marketed by the Rohm and Haas Company; the condensation products of aliphatic alcohols with from about 1 to about 25 moles of ethylene oxide; the condensation products of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol, the hydrophobic portion of these compounds preferably having a molecular weight of from about 1500 to about 1800 and exhibiting water insolubility; the condensation products of ethylene oxide with the product resulting from the reaction of propylene oxide and ethylenediamine; alkylpolysaccharides and alkylpolysaccharides having a hydrophobic group containing from about 6 to about 30 carbon atoms and a polysaccharide, e.g., a polyglycoside, hydrophilic group containing from about 1.3 to about 10 saccharide units; alkyl ethoxy carboxylates of the formula RO(CH2CH2O)xCH2COOxe2x80x94M+ wherein R is a C12 to C16 alkyl group, x ranges from 0 to about 10, and having an ethoxylate distribution by weight that when x is 0 is less than about 20% and when x is greater than 7 is less than about 25%, the average x is from about 2 to 4 when the average R is C13 or less, and the average x is from about 3 to 6 when the average R is greater than C13, and M is a cation, preferably chosen from alkali metal, ammonium, mono-, di-, and tri-ethanolammonium, most preferably from sodium, potassium, ammonium, and mixtures thereof with magnesium ions.
Another suitable composition includes a polyhydroxy fatty acid amide surfactant of the structural formula: 
wherein: R1 is H, C1-C4 hydrocarbyl, 2-hydroxy ethyl, 2-hydroxy propyl, or a mixture thereof, and R2 is a C5-C31 hydrocarbyl, and Z is a polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least 3 hydroxyls directly connected to the chain, or an alkoxylated derivative thereof. Other ampholytic surfactants may also be included in the compositions.
Another suitable composition includes alkyl amphocarboxylic acids of the formula: 
wherein R is a C8-C18 alkyl group, and Ri is of the general formula: 
wherein R1 is a (CH2)xCOOM or CH2 CH 2OH, and x is 1 or 2 and M is preferably chosen from alkali metal, alkaline earth metal, ammonium, mono-, di-, and tri-ethanolammonium, most preferably from sodium, potassium, ammonium, and mixtures thereof with magnesium ions. The preferred R alkyl chain length is a C10 to C14 alkyl group. Suitable such alkyl amphodicarboxylic acids include the amphoteric surfactant Miranol.RTM, and .C2M Conc. manufactured by Miranol, Inc., Dayton, N.J.
Another suitable composition includes a zwitterionic surfactant, e.g., derivatives of secondary and tertiary amines, derivatives of heterocyclic secondary and tertiary amines, or derivatives of quaternary ammonium, quaternary phosphonium or tertiary sulfonium compounds. Ampholytic and zwitterionic surfactants are generally used in combination with one or more anionic and/or nonionic surfactants. If included in the compositions of the present invention, these additional surfactants are typically present at a concentration of from about 1% to about 15%, preferably from about 2% to about 10% by weight of the composition. The composition may further include a buffering agent, e.g., an amino acid, a lower alcohol amine, 2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methylpropanol, 2-amino-2-methyl-1,3-propanediol, tris-(hydroxymethyl)aminomethane (a.k.a. tris) and disodium glutamate, N-methyl diethanolamine, 1,3-diamino-2-propanol N,Nxe2x80x2-tetramethyl-1,3-diamino-2-propanol, N,N-bis(2-hydroxyethyl)glycine (a.k.a. bicine), and N-tris (hydroxymethyl)methyl glycine (a.k.a. tricine), and mixtures thereof, at a level of from about 0.1% to 15% by weight.
A saccharide may be included in an amount from about 0.1% to about 5.0% by weight, e.g., sucrose, cellobiose, lactulose, maltose (malt sugar), lactose, gluconic acid, glucose, fructose, galactose, xylose, arabinose and ribose. The composition of this invention can also contain a certain cationic quarternary ammonium surfactants, magnesium ions in amounts from about 0.01% to about 4%, alcohols such as ethyl alcohol and propylene glycol at a level of from 0% to about 15%, diluents such as ammonium chloride, sodium chloride, potassium chloride, etc., and solvents including water, lower molecular weight alcohols, such as ethyl alcohol, isopropyl alcohol, etc. Compositions herein will typically contain up to about 45%, preferably from about 20% to about 40%, most preferably from about 25% to about 35%, of water.
Another suitable formulation as described for the product UltraPalmolive(copyright), which is: water, ammonium laureth sulfate, lauryl polyglucose, sodium and magnesium, dodecylbenzenesulfonate, SD alcohol 3A, sodium xylenesulfonate, lauramide/myristamide MEA, sodium chloride, fragrance, trisodium HEDTA, and DandC orange no 4.
In addition, the addition of a conventional dye can alter the strand, drop, or sheet, or color of the bubble to a predetermined color. The application of such dyes to surfactant compositions are well known to those skilled in the art.
The invention will be further illustrated by the following examples of its practice.
A commercially available bubble-forming solution, Miracle Bubble(copyright), was tested using a toy bubble-blowing wand six inches long with a xc2xd inch ring. Bubbles were formed in accordance with the manufacturer""s instructions and their longevity measured. It was observed that the bubbles varied in size and maintained their integrity from between about 1 second to about 60 seconds before popping, generally after floating and then bursting upon contact with a dry object. It was also observed that upon bursting the bubble components were not readily or easily visible to the naked eye.